1 files changed, 96 insertions, 1 deletions

diff --git a/src/ltm.js b/src/ltm.js
index ebc0348..5d93e28 100644
--- a/src/ltm.js
+++ b/src/ltm.js
@@ -4,7 +4,102 @@
 const lobject = require('./lobject.js');
 const TValue  = lobject.TValue;
 const Table   = lobject.Table;
+const ldo     = require('./ldo.js');
+const lstate  = require('./lstate.js');
+const lua     = require('./lua.js');
+const CT      = lua.constant_types;
 
 
+const TMS = {
+    TM_INDEX:    "__index",
+    TM_NEWINDEX: "__newindex",
+    TM_GC:       "__gc",
+    TM_MODE:     "__mode",
+    TM_LEN:      "__len",
+    TM_EQ:       "__eq",  /* last tag method with fast access */
+    TM_ADD:      "__add",
+    TM_SUB:      "__sub",
+    TM_MUL:      "__mul",
+    TM_MOD:      "__mod",
+    TM_POW:      "__pow",
+    TM_DIV:      "__div",
+    TM_IDIV:     "__idiv",
+    TM_BAND:     "__band",
+    TM_BOR:      "__bor",
+    TM_BXOR:     "__bxor",
+    TM_SHL:      "__shl",
+    TM_SHR:      "__shr",
+    TM_UNM:      "__unm",
+    TM_BNOT:     "__bnot",
+    TM_LT:       "__lt",
+    TM_LE:       "__le",
+    TM_CONCAT:   "__concat",
+    TM_CALL:     "__call",
+    TM_N:        26
+};
 
-module.exports = {}
\ No newline at end of file
+const luaT_callTM = function(L, f, p1, p2, p3, hasres) {
+    let result = p3;
+    let func = L.top;
+
+    L.stack[L.top] = f;      /* push function (assume EXTRA_STACK) */
+    L.stack[L.top + 1] = p1; /* 1st argument */
+    L.stack[L.top + 2] = p2; /* 2nd argument */
+    L.top += 3;
+
+    if (!hasres)  /* no result? 'p3' is third argument */
+        L.stack[L.top++] = p3;  /* 3rd argument */
+
+    if (ci.callstatus & lstate.CIST_LUA)
+        ldo.luaD_call(L, func, hasres);
+    else
+        ldo.luaD_callnoyield(L, func, hasres);
+
+    if (hasres) {
+        L.stack[result] = L.stack[--L.top];
+    }
+};
+
+const luaT_callbinTM = function(L, p1, p2, res, event) {
+    let tm = luaT_gettmbyobj(L, p1, event);
+    if (tm.ttisnil())
+        tm = luaT_gettmbyobj(L, p2, event);
+    if (tm.ttisnil()) return false;
+    luaT_callTM(L, tm, p1, p2, res, 1);
+    return true;
+}
+
+const luaT_trybinTM = function(L, p1, p2, res, event) {
+    if (!luaT_gettmbyobj(L, p1, p2, res, event)) {
+        throw new Error("TM error"); // TODO: luaG_error
+    }
+}
+
+const luaT_callorderTM = function(L, p1, p2, event) {
+    if (!luaT_callbinTM(L, p2, p2, L.top, event))
+        return -1;
+    else
+        return !l_isfalse(L.stack[L.top]) ? 1 : 0;
+}
+
+const luaT_gettmbyobj = function(L, o, event) {
+    let mt;
+    switch(o.ttnov()) {
+        case CT.LUA_TTABLE:
+        case CT.LUA_TTUSERDATA:
+            mt = o.value.metatable;
+        default:
+            // TODO: mt = G(L)->mt[ttnov(o)];
+    }
+
+    return mt ? mt.__index(mt, event) : ldo.nil;
+}
+
+module.exports = {
+    TMS:              TMS,
+    luaT_callTM:      luaT_callTM,
+    luaT_callbinTM:   luaT_callbinTM,
+    luaT_trybinTM:    luaT_trybinTM,
+    luaT_callorderTM: luaT_callorderTM,
+    luaT_gettmbyobj:  luaT_gettmbyobj
+}
\ No newline at end of file